A young boy named Yuuya decides to peep at his crush Mariko, only to witness a horrific sight soon after: the girl has a talking face on her bare chest. Wanting to ascertain what he has seen, Yuuya eavesdrops again the next night but is caught in the act by Mariko. Subsequently, she reveals that the face is that of her homeroom teacher, whom she claims to have killed herself. Terrified yet intrigued, Yuuya finds himself delving deeper into this enigma. [Written by MAL Rewrite]